1. Field of the Invention
The present invention relates to a post-mix soft drink dispenser system suitable for use in a refrigerator.
2. Description of the Prior Art
Heretofore, attempts have been made to provide post-mix dispenser systems for use in refrigerators which are compact and easily incorporated into existing refrigerators and which are capable of dispensing post-mix soft drink beverages of suitable quality. However, due to various design features of these prior art systems the above objectives have never been satisfactorily achieved. Examples of such systems can be found in the following U.S. Pat. Nos. 2,785,546 to Bauerlein, issued Mar. 19, 1957; 2,894,377 to Shikles, Jr. et al, issued July 14, 1959; 2,823,833 to Bauerlein, issued Feb. 18, 1958; 3,292,822 to Crowder et al, issued Dec. 20, 1966; 3,756,473 to Donahue, issued Sept. 4, 1973; and 3,942,685 to Lidner, issued Mar. 9, 1976.
U.S. Pat. Nos. 2,785,546, and 2,823,833 to Bauerlein, 3,756,473 to Donahue, and 3,942,685 to Lidner disclose post-mix beverage dispenser units designed for use in refrigerators. These dispenser systems will selectively dispense either ice water, or a mixture of syrup concentrate and water. There are no provisions in the systems of Bauerlein for dispensing carbonated water or carbonated beverages. In addition, the water for the systems of Bauerlein is provided through a pipe which must pass through the wall of the refrigerator making retro-fitting of the Bauerlein system somewhat complex. One glaring disadvantage of the Bauerlein systems is that the syrup concentrate is contained in a refillable container rather than in a disposable syrup package, which creates cleaning problems and unsanitary conditions.
The dispenser system described in U.S. Pat. No. 2,894,377 to Shikles, Jr. et al has more versatile dispensing capabilities than the dispenser systems of Bauerlein, Donahue and Lidner described above, since it can dispense carbonated water and carbonated post-mix beverages in addition to tap water and post-mix combinations of tap water and syrup. However, the Shikles, Jr. et al system still suffers from certain disadvantages. For example, the Shikles, Jr. et al system requires an external water supply which must be piped in through the walls of a refrigerator making retro-fitting of the system more complicated than desirable. In addition, although the syrup packages of Shikles, Jr. et al are removeable, they are not as easily inserted into the system as desirable, since several connections are necessary between the syrup package of Shikles, Jr. et al and other components of the system. Furthermore, the syrup package of Shikles, Jr. et al will not provide the necessary controlled rate of flow needed to obtain a high quality of beverage with the same proportions of carbonated water and syrup for every beverage dispensed.
U.S. Pat. No. 3,292,822 to Crowder et al disclosed in FIGS. 17 and 18 a post-mix carbonated beverage dispenser system contained within the door of a refrigerator including a manually refillable water reservoir for the carbonator and disposable syrup packages. However, the method of inserting the syrup packages into the system is somewhat cumbersome, the valving system has limited capabilities, and the syrup is not dispensed at a satisfactorily controllable rate of flow.
Prior to the present invention the use of a flow rate control tube in the syrup container of a post-mix dispenser for providing an even rate of flow of syrup from the container into a receptacle was generally known. An example of a system of this type is disclosed in U.S. Pat. No. 2,708,533 to Nicholas. Nicholas discloses the broad concept of providing a flow control tube 76 in the syrup tank of a post-mix beverage system having its open or bottom end precisely positioned at a predetermined level above the discharge opening of the tank in order to provide a substantially constant rate of flow of the syrup being dispensed from the tank. The Nicholas patent also discloses in FIG. 2 that the syrup tank of his invention may be a disposable tin can that is filled at a central distributing plant and delivered in a completely sealed condition to the location of the dispensing system. As illustrated in FIG. 2 of Nicholas, the bottom of the tin can is rupturable by puncturing elements associated with the dispenser valve and the top of the can is provided with a knockout 118 into which stopper 74 and flow control tube 76 is inserted just prior to the dispensing operation. The flow control tube 76 is positioned within the container at a predetermined position determined by graduations 124 on the flow control tube which instructs an operator as to the proper position of the tube for preselected different flow rates for syrups of different Brix values.
Although, once the system of Nicholas is assembled, it operates in a very satisfactory manner for controlling flow rate, it does suffer from certain disadvantages. For example, in the Nicholas patent the flow control tube is a completely separate item from the syrup package which is shipped from the distributing plant to the point of use. Thus, the flow control tube 76 in Nicholas system requires special assembly at the point of use and skilled adjustment of its position within the syrup container. While it might be possible for an operator in a commercial establishment to learn how to properly insert the flow control tube, the occasional user of the system would have difficulty inserting the flow control tube in the correct position for the different Brix values of syrups to be dispensed. In addition, the syrup container of Nicholas could be refilled through the knockout portion 118 which would lead to problems of improper or inadequate sanitation. Still further, if the temperature of the syrup container of Nicholas is elevated, syrup will rise up tube 76 and spill over through the top thereof.
Other examples of the use of flow control or vent tubes in syrup packages can be found in U.S. Pat. No. 3,258,166 to Kuckens, issued June 28, 1966 and U.S. Pat. No. 3,991,219 to Kuckens, issued Nov. 19, 1976. Each of these patents disclose inverted containers having flow control vent tubes formed therein. However, the vent tubes in each of these patents are completely open to the atmosphere. That is, no means are provided for precluding the flow of liquid up the vent tubes. Thus, at elevated temperatures the head-space of gas above the liquid in the containers will create a back-pressure forcing the liquid up the vent tubes causing spillage.
An additional U.S. Pat. No. 3,807,607 to Kuckens issued Apr. 30, 1974 discloses a syrup container 1 having a vent tube 11 therein and a gas responsive check valve 12 in the top of vent tube 11. The check valve 12 of Kuckens is provided to inhibit flow of syrup up tube 11 when container 1 is being refilled in contrast to precluding flow up the tube in response to container 1 being heated to an elevated temperature. Applicant has discovered that the location of valve 12 of Kuckens at the top of tube 11 is unsatisfactory, if fluid flow up the tube 11 were to be caused by an elevated container temperature. In such a case fluid might flow substantially all of the way to valve 12 at the top of vent tube 11 before valve 12 closed. This would result in the accumulation of syrup on the inner walls of tube 11 causing clogging and/or contamination. Moreover, as stated hereinbefore, the Kuckens valve 12 is not disclosed as being provided to preclude flow up tube 11 in response to an elevated container temperature. In short, the Kuckens syrup dispensing apparatus is not designed for use in a refrigerator where the opening and closing of the refrigerator door may cause elevated syrup package temperatures resulting in the tendency of syrup to flow up the vent tube in response to those elevated temperatures.
Check valves have also been used heretofore in vent tubes of containers for dispensing products other than syrup. However, these check valves were utilized to preclude spilling of liquid when the container is inverted to an upright non-dispensing position. The designers of these prior art devices were not concerned nor cognizant of the problem of fluid spillage of liquid due to an elevated container temperature and a resulting flow of liquid up the vent tube. Examples of such prior art containers can be found in U.S. Pat. Nos. 600,327 to Winters, issued Mar. 8, 1898; 2,283,652 to Schwarzkopf issued May 19, 1942; 2,336,313 to Swan issued Dec. 7, 1943; and 2,822,962 to Poitras issued Feb. 11, 1958.